1. Field of the Invention
The invention relates to contactless data links which are used for transmission of high frequency signals or data between units movable against each other, which for example are rotating units like rotary joints. These contactless data links have to be adjusted or the adjustment has to be checked to meet the requirements of EMC standards, and to obtain a high data rate, high reliability, and low transmission losses or bit error rates. These adjustment procedures require specific tools and must be adapted to the contactless data links.
2. Description of Relevant Art
A contactless data link is disclosed in the U.S. Pat. No. 6,301,324 B1. This contactless data link is also called a contactless slip ring. It has a circular-shaped transmission line like a stripline at the rotating part which is coupled to a transmitter. The stationary part is a small receiver arranged in close proximity to the transmission line. The data rate is limited to about 2 Gb per second, which can be estimated from the disclosed bandwidth filter having a frequency range between 500 MHz and 1 GHz. For higher data rates, the transmission line may be modified as disclosed in EP 1 012 899 A. Here instead of a stripline, a pattern of narrower and wider sections is used. This pattern has a bandpass characteristic which suppresses unwanted noise.